/**
 * Active expiration: background sweeper that deletes expired keys in batches.
 * Also prunes expired hash fields (redis_hash_field_ttl) and drops now-empty hashes.
 */
import type Database from '../storage/sqlite/driver.ts';
export interface ExpirationSweeperOptions {
    db: Database;
    clock: () => number;
    /** Defaults to 1000. */
    sweepIntervalMs?: number;
    /** Defaults to 500. */
    maxKeysPerSweep?: number;
}
export interface ExpirationSweeper {
    start: () => void;
    stop: () => void;
}
export declare function createExpirationSweeper(opts: ExpirationSweeperOptions): ExpirationSweeper;